The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Hybrid powertrain systems include electric power systems including high voltage electric energy devices that supply electric power to multiphase electric motors via electric power inverters that convert stored DC electric power to AC electric power. The multiphase electric motors can be used to provide tractive torque and provide power to accessory devices, including, e.g., auxiliary hydraulic pumps and HVAC compressors.
Known motor control systems may include a position feedback sensor such as a resolver or encoder to monitor rotational speed and position of an electric motor. Feedback devices and associated interface circuits add complexity to a motor control system in the form of added components, added weight, and added wiring harness complexity. The additional system complexity may affect assembly time, serviceability, and in-use performance.
An electric power system can use an electric motor control technology such as vector motor control to control operation of electric motors. A vector motor control scheme is a computationally intensive motor control scheme that maps the phase voltages and currents of a three-phase motor into a two-axis coordinate system. One known configuration for exciting a multiphase-phase AC electric motor using a vector control scheme is a multiphase-phase electric power inverter including power transistors that transform DC electric power to multiphase AC output power. Vector control requires rotor position information, which can be obtained via a feedback device or position sensor.
Known position sensorless control systems determine rotor position information using electromagnetic characteristics of the multiphase AC machine, thus eliminating a need for a position feedback sensor and its associated interface circuits.
Control systems for powertrain systems including hybrid powertrain systems monitor operation to detect occurrence of faults in components and systems that can affect emissions.